Four-way change-over valve for air conditioner and service valve therewith

ABSTRACT

A four-way change-over valve for an air conditioner has first to fourth piping holes sequentially arranged on a concentric circle at a predetermined pitch in a planar portion of a valve seat formed in a thick disk shape as one portion of a valve case. The change-over valve also has a rotary valve rotatably arranged on an upper face of this valve seat and having at least one communicating groove for independently connecting two adjacent piping holes of the four piping holes to each other. Cooling and heating operations of the air conditioner are switched by rotating the rotary valve. A service valve with a four-way change-over valve for an air conditioner is characterized in that both service valves on liquid and gas sides of a refrigerant circuit are integrated with each other and are further integrated with the four-way change-over valve as one valve unit with one valve seat as a common valve seat. In accordance with such valve structures, the four-way change-over valve has a simplified structure and is made compact. Further, the service valve is also made compact and operability of the service valve is improved.

This is a Divisional Application of application Ser. No. 08/147,775,filed Nov. 5, 1993, now U.S. Pat No. 5,462,085.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a four-way change-over valve for an airconditioner used to switch cooling and heating operations in the airconditioner utilizing a refrigerating cycle of a heat pump type. Thepresent invention also relates to a service valve with a four-waychange-over valve for an air conditioner. The present invention furtherrelates to a valve attached to an outdoor unit of an air conditioner ofa separating type in which the same piping function is fulfilled byusing one compact valve instead of two general valves.

2. Description of the Related Art

In the general structure of a four-way change-over valve utilizing arefrigerant pressure, a valve sheet having a U-shape in cross sectionand the same curved surface as a cylinder must be accurately soldered toa central lower portion of a cylinder. Further, this structure has aconnecting means for connecting a valve slide arranged on an upper faceof the valve sheet to a piston rod or a bracket such that the valveslide is set in a press contact state at any time and can be smoothlyslid. This structure also has a fixing means for fixing piston rings toboth ends of the piston rod. However, operability of each of theconnecting and fixing means is greatly reduced since the valve slide islocated in a central portion of the cylinder.

In this structure, differences in pressure between chambers of thecylinder are caused by using magnetomotive force as attractive force andresilient force of a spring as repulsive force in a switching operationof the change-over valve and one generation of the magnetomotive forceand demagnetization. Thus, the valve slide is slid at all strokes.Accordingly, in a heating state of an air conditioner, no pressuredifferences between the chambers for making a heating circuit can beheld unless an electric current continuously flows through a solenoid.Therefore, no valve slide can be held in the heating state.

In a change-over valve using a wax type thermoelement, pressures withthe chambers are increased by heating the thermoelement in a drivingsource. Accordingly, an error in operation of the change-over valvetends to be caused, or a switching operation of the change-over valvetends to be unstable by the influence of an outside air temperature.Further, performance of the change-over valve is greatly influenced by aseal state between a shaft in a shaft core portion and the wax typethermoelement. However, it is very difficult to reliably seal the shaftand the wax type thermoelement when the change-over valve ismanufactured. As a result, cost of the change-over valve is increased.

In a change-over valve using a stepping motor, etc., the stepping motoris very expensive so that cost of the four-way change-over valve isincreased.

In each of change-over valves shown in Japanese Utility ModelApplication Laying Open (KOKAI) No. 58-127276 and Japanese PatentApplication Laying Open (KOKAI) No. 59-155669, an electromagnetic coilis arranged outside a device body through a pipe-shaped guide. A plungeris inserted into this guide and a valve body within the device body isswung through an operating plate. Therefore, the device body is madecompact, but the electromagnetic coil is large-sized so that theelectromagnetic coil projects toward the exterior of the device body.Accordingly, the device body and the electromagnetic coil areunbalanced. Further, it is very troublesome to airtightly connect thedevice body to the electromagnetic coil through the guide. Accordingly,such a structure is not practically used.

In another general valve structure, two valves are attached onto theside of an outdoor unit of a general air conditioner of a separatingtype. The two valves are composed of a 3/8" valve connected to afour-way change-over valve and a 1/4" valve connected to a capillarytube. Piping of these valves is performed between the outdoor unit andan indoor unit when the air conditioner is arranged.

For example, Japanese Utility Model Application Laying Open (KOKAI) Nos.61-54563 and 61-54564 show a proposed valve structure for integratingtwo valves as one valve unit.

In the general valve structure using two valves, the two valves areindependently manufactured so that cost of the valve structure isincreased and a wide space for attaching the valves is required.Further, a valve having a shaft shape is used within the valve structureso that the valve structure is increased in height. Further, there areno opening and closing displays with respect to the valves so that nooperator can accurately attach the valves to the air conditioner unlessthe operator is a technical expert for attachment.

In the valve shown in each of Japanese Utility Model Application LayingOpen (KOKAI) Nos. 61-54563 and 61-54564, one valve device body is formedin a cylindrical shape. However, a valve within this valve device bodyis constructed by a valve having a shaft shape. In Japanese UtilityModel Application Laying Open (KOKAI) No. 61-54563, a main valve rod hasa second valve rod therein and is mounted to the valve device body suchthat the main valve rod functions as two valves. In contrast to this, inJapanese Utility Model Application Laying Open (KOKAI) No. 61-54564, aring-shaped valve body is formed such that an elongated central valverod is inserted into a central portion of the ring-shaped valve body.This ring-shaped valve body is mounted to the valve device body.Connection holes formed in a central portion and a lower end portion ofthe valve device body are opened and closed by each of the valve rods.However, each of the valve structures in these two applications iscomplicated so that it takes much time and labor to process each of thevalve structures.

Further, in each of these valve structures, the shaft-shaped valve isarranged as a double structure within the valve device body so that eachof the valve structures is increased in height. Accordingly, pipingconnection holes connected to an indoor unit are directed outward sothat no pipes are preferably arranged in appearance.

SUMMARY OF THE INVENTION

It is therefore a first object of the present invention to provide acompact four-way change-over valve for an air conditioner in which it iseasy to process piping holes of a valve seat and assemble the four-waychange-over valve and no complicated mechanism for utilizing a pressuredifference is required.

A second object of the present invention is to provide a compact servicevalve with a four-way change-over valve manufactured easily and cheaply.

A third object of the present invention is to provide a compact valvefor an air conditioner in which the valve has a good external appearancein an attaching state of this valve attached to the air conditioner andis easily treated and simply operated.

In accordance with a first structure of the present invention, the abovefirst object can be achieved by a four-way change-over valve for an airconditioner comprising:

first to fourth piping holes sequentially arranged on a concentriccircle at a predetermined pitch in a planar portion of a valve seatformed in a thick disk shape as one portion of a valve case; and

a rotary valve rotatably arranged on an upper face of this valve seatand having at least one communicating groove for independentlyconnecting two adjacent piping holes of the four piping holes to eachother;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve.

In accordance with a fourth structure of the present invention, theabove first object can be also achieved by a four-way change-over valvefor an air conditioner comprising:

first to fourth piping holes sequentially arranged on a concentriccircle at an equal pitch in a planar portion of a valve seat formed in athick disk shape as one portion of a valve case; and

a rotary valve rotatably arranged on an upper face of this valve seatand symmetrically having communicating grooves for independentlyconnecting two adjacent piping holes of the four piping holes to eachother;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve.

For example, a typical means for rotating the rotary valve isconstructed by a compact DC motor. In this rotating means, a rotationalspeed of the DC motor is reduced by gears and an operating shaft isarranged in a central upper portion of the rotary valve. The rotaryvalve is rotated by rotating the operating shaft. In another rotatingmeans, a tooth form may be arranged in an outer circumference of therotary valve so that the rotary valve can be rotated by using this toothform.

The two adjacent piping holes of the first to fourth piping holes can bemutually switched by rotating the rotary valve 90°. An operation of thefour-way change-over valve will be explained in detail on the basis ofembodiments of the present invention.

In accordance with a fifth structure of the present invention, the abovesecond object can be achieved by a service valve with a four-waychange-over valve for an air conditioner characterized in that bothservice valves on liquid and gas sides of a refrigerant circuit areintegrated with each other and are further integrated with the four-waychange-over valve as one valve unit with one valve seat as a commonvalve seat.

In accordance with a sixth structure of the present invention, the abovesecond object can be also achieved by a service valve with a four-waychange-over valve for an air conditioner comprising:

first to fourth piping holes formed on a lower face of a valve seathaving a thick disk shape and sequentially arranged on a concentriccircle at a predetermined pitch;

three piping holes among the four piping holes being communicated with aside portion of the valve seat; and

a rotary valve rotatably arranged on the lower face of the valve seatand having one or two communicating grooves independently connecting twoadjacent piping holes of the four piping holes to each other andsymmetrically arranged;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve;

the service valve further comprising:

two piping connection holes formed on an upper face of the valve seatsuch that the two piping connection holes are shifted from each other ona concentric circle;

one of the two piping connection holes being connected to a piping holeexcept for the three piping holes communicated with the side portion onthe lower face of the valve seat;

the other piping connection hole being communicated with the sideportion of the valve seat;

a disk shutter rotatably arranged on the upper face of the valve seatand having two passing holes in positions corresponding to the pipingconnection holes; and

a shutter cover arranged above the disk shutter and having piping holesin positions corresponding to the two passing holes of the disk shutter;

cooling and heating operable states of the air conditioner and anoperating state of the air conditioner except for the cooling andheating operable states being switched by rotating the disk shutter.

In accordance with a ninth structure of the present invention, the abovesecond object can be also achieved by a service valve With a four-waychange-over valve for an air conditioner comprising:

a valve chest formed in a central portion of a valve seat having a thickdisk shape;

first to fourth piping holes each formed in an outer circumferentialportion of the valve chest and sequentially arranged at a predeterminedpitch In four directions;

three piping holes of the four piping holes being communicated with aside portion of the valve seat; and

a rotary valve rotatably arranged within the valve chest in the centralportion of the valve seat and independently connecting two adjacent,piping holes among the four piping holes to each other;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve;

the service valve further comprising:

two piping connection holes formed on an upper face of the valve seatsuch that the two piping connection holes are shifted from each other ona concentric circle;

one of the two piping connection holes being connected to a piping holeexcept for the three piping holes communicated with the side portion ofthe valve seat;

the other piping connection hole being communicated with the sideportion of the valve seat;

a disk shutter rotatably arranged on the upper face of the valve seatand having passing holes in positions corresponding to the pipingconnection holes; and

a shutter cover arranged above the disk shutter and having piping holesin positions corresponding to the two piping connection holes;

cooling and heating operable states of the air conditioner and anoperating state of the air conditioner except for the cooling andheating operable states being switched by rotating the disk shutter.

In the above service valve with the four-way change-over valve in thepresent invention, two adjacent piping holes of the first to fourthpiping holes on the lower face of the valve seat are mutually switchedby rotating the rotary valve 90° so that cooling and heating operationsof the air conditioner can be switched. The disk shutter on the upperface of the valve seat is rotated by rotating a driving shaft from theexterior of the shutter cover. Thus, it is possible to suitably andselectively switch communicating states of the two piping connectionholes on the upper face of the valve seat and the two piping holes ofthe shutter cover.

Accordingly, when the air conditioner is arranged and moved, alloperations of the air conditioner can be performed by only changingrotational positions of the disk shutter through the driving shaft indischarge of air and collection of refrigerant.

The above third object can be achieved by a fourteenth structure of thepresent invention. In the fourteenth structure, a valve body is formedin the shape of a flat case and a disk shutter having two passing holesis rotatably arranged within the valve body. Communicating holes areswitched by rotating the disk shutter. Further, piping connection holesare formed on a side face of the flat case valve body so that the entirevalve is made compact.

Namely, in accordance with the fourteenth structure of the presentinvention, the above third object can be achieved by a valve for an airconditioner comprising:

a flat valve case having a circular recessed portion with a shallowbottom on an upper face thereof and having two piping connection holesshifted from each other at a phase angle of 90° or 120° on a concentriccircle;

a disk shutter rotatably arranged within the circular recessed portionof the flat valve case and having passing holes in positionscorresponding to the piping connection holes;

the disk shutter further having a driving shaft in a central portionthereof; and

a valve cover having piping holes in positions corresponding to the twopiping connection holes;

the valve cover further having a shaft hole in a central portion thereofformed such that the driving shaft can be rotatably fitted into thisshaft hole; and

the valve cover being fixed to the valve case such that the valve coverairtightly covers the disk shutter and the driving shaft from above.

In the fourth structure of the present invention, the disk shutterwithin the valve case is rotated by rotating the driving shaft from theexterior of the valve cover. Thus, it is possible to suitably andselectively switch communicating states of the piping connection holeson a lower face of the valve case and the piping holes of the valvecover.

Accordingly, when the air conditioner is arranged and moved, alloperations of the air conditioner can be performed by only changingrotational positions of the disk shutter through the driving shaft indischarge of air and collection of refrigerant.

Further objects and advantages of the present invention will be apparentfrom the following description of the preferred embodiments of thepresent invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional side view of a general four-waychange-over valve utilizing differences between refrigerant pressures;

FIG. 2 is a cross-sectional plan view of a general four-way change-overvalve utilizing a disk-shaped base and a valve body having a bowl shape;

FIG. 3 is a longitudinal sectional side view of the four-way change-overvalve shown in FIG. 2;

FIG. 4 is a refrigerant circuit diagram of a general air conditioner ata cooling time thereof;

FIG. 5 is a longitudinal sectional side view of a general service valve;

FIG. 6 is a longitudinal sectional side view of a four-way change-overvalve in accordance with a first embodiment of the present invention;

FIG. 7 is a bottom view of the four-way change-over valve shown in FIG.6 at a cooling time of an air conditioner;

FIG. 8 is a bottom view of the four-way change-over valve shown in FIG.6 at a heating time of the air conditioner;

FIG. 9a is a circuit diagram of the air conditioner into which thefour-way change-over valve in the present invention is assembled when acooling operation is performed;

FIG. 9b is a circuit diagram of the air conditioner into which thefour-way change-over valve in the present invention is assembled when aheating operation is performed;

FIG. 10 is a longitudinal sectional side view showing one example of aservice valve with a four-way change-over valve in accordance with asecond embodiment of the present invention;

FIG. 11 is an exploded perspective view showing the service valve withthe four-way change-over valve in the second embodiment of the presentinvention;

FIG. 12 is an exploded perspective view showing a service valve with afour-way change-over valve in accordance with a third embodiment of thepresent invention;

FIG. 13 is a central cross-sectional plan view showing an assembly stateof the service valve with the four-way change-over valve shown in FIG.12;

FIG. 14 is a longitudinal sectional side view showing an assembly stateof the service valve with the four-way change-over valve shown in FIG.12;

FIG. 15 is a refrigerant circuit diagram of an air conditioner intowhich the service valve with the four-way change-over valve in thepresent invention is assembled at a cooling time of the air conditioner;

FIG. 16 is an exploded perspective view of a valve for an airconditioner in accordance with a fourth embodiment of the presentinvention;

FIG. 17 is a perspective view of the valve for an air conditioner inaccordance with the fourth embodiment of the present invention;

FIG. 18 is a longitudinal sectional side view of the valve for an airconditioner in accordance with the fourth embodiment of the presentinvention;

FIG. 19 is a plan view showing a case in which a valve cover in thefourth embodiment of the present invention is attached to the valve foran air conditioner;

FIG. 20 is a front view showing only the valve cover of FIG. 19 in crosssection; and

FIG. 21a to 21d are plan views each showing the relation in positionbetween a disk shutter and piping connection holes of a valve case inthe fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of a four-way change-over valve for an airconditioner and a service valve therewith in the present invention willnext be described in detail with reference to the accompanying drawings.

FIG. 1 shows the construction of a four-way change-over valve used atpresent. As shown in FIG. 1, the change-over valve has a first pipinghole 31 in a central upper portion of a cylindrical cylinder 30. Thechange-over valve also has a valve sheet 35 having a U-shape in crosssection and arranged in a turning-over state in a central lower portionof the cylinder 30. The valve sheet 35 has three holes composed of asecond piping hole 32, a third piping hole 33 and a fourth piping hole34 arranged in series. A valve slide 36 having a bowl shape is arrangedon an upper face of this valve sheet 35. A piston rod 39 has pistonrings 37 and 38 on both sides of the valve sheet 35. The piston rod 39is connected to the valve slide 36. Chambers 40, 41 and 42 within thecylindrical cylinder 30 are partitioned by the piston rings 37 and 38.Refrigerant pressures of the chambers 40 to 42 are switched by using anelectromagnetic valve 43. Thus, the valve slide 36 is slid through thepiston rod 39 so that cooling and heating operations of an airconditioner are switched. For example, such a switching system is shownin Japanese Patent Application Laying Open (KOKAI) No. 61-62677.

Japanese Utility Model Application Laying Open (KOKAI) No. 4-68264 showsanother four-way change-over valve. In this change-over valve, a drivingsource is constructed by a wax type thermoelement having a shaft in ashaft core portion as a driving means of the valve slide 36. The drivingsource is also constructed by a heater arranged such that an outercircumferential portion of the wax type thermoelement is covered withthe heater. A bracket is connected to the driving source. The valveslide is slid through the bracket. Japanese Patent Application LayingOpen (KOKAI) No. 4-190058 also shows another four-way change-over valve.In this change-over valve, a screw shaft is moved by a stepping motor, ageared motor or a linear motor. The valve slide is slid through abracket connected to an end tip of this screw shaft. A basicconstruction of each of bodies of these four-way change-over valves issimilar to that shown in FIG. 1.

Each of FIGS. 2 and 3 shows an electromagnetic change-over valveapplicable to an air conditioner. For example, such a valve is shown inJapanese Utility Model Application Laying Open (KOKAI) No. 58-127276. Inthis change-over valve, a device body 51 is constructed by a disk-shapedbase 49 and a cylindrical body 50 having a bottom. The base 49 has aplurality of through holes such as four through holes 45, 46, 47 and 48.A valve body 52 is formed in an elliptical bowl shape to open and closethe through holes. The valve body 52 is slidably arranged in a planarportion of the disk-shaped base 49 in the device body 51. This valvebody 52 is moved by operating an electromagnetic coil 53 arrangedoutside the device body 51. A plunger 55 is arranged within apipe-shaped guide 54 extending through an outer circumferential wall ofthe device body 51. Thus, one end portion of the valve body 52 is swungthrough an operating plate 56.

Japanese Patent Application Laying Open (KOKAI) No. 59-155669 shows amodified example of the change-over valve in which a valve body having abowl shape is slid on the above-mentioned disk-shaped base.

In the above general structure of the four-way change-over valveutilizing a refrigerant pressure, the valve sheet 35 having a U-shape incross section and the same curved surface as the cylinder must beaccurately soldered to a central lower portion of the cylindricalcylinder 30. Further, this structure has a connecting means forconnecting the valve slide 36 arranged on the upper face of the valvesheet 35 to the piston rod 39 or a bracket such that the valve slide 36is set in a press contact state at any time and can be smoothly slid.This structure also has a fixing means for fixing the piston rings 37and 38 to both ends of the piston rod 39. However, operability of eachof the connecting and fixing means is greatly reduced since the valveslide 36 is located in a central portion of the cylinder 30.

In this structure, differences in pressure between the chambers 40 to 42of the cylindrical cylinder are caused by using magnetomotive force asattractive force and resilient force of a spring as repulsive force in aswitching operation of the change-over valve and one generation of themagnetomotive force and demagnetization. Thus, the valve slide is slidat all strokes. Accordingly, in a heating state of the air conditioner,no pressure differences between the chambers 40 to 42 for making aheating circuit can be held unless an electric current continuouslyflows through a solenoid. Therefore, no valve slide can be held in theheating state.

In the change-over valve using the wax type thermoelement, the pressureswith the chambers are increased by heating the thermoelement in thedriving source. Accordingly, an error in operation of the change-overvalve tends to be caused, or a switching operation of the change-overvalve tends to be unstable by the influence of an outside airtemperature. Further, performance of the change-over valve is greatlyinfluenced by a seal state between the shaft in the shaft core portionand the wax type thermoelement. However, it is very difficult toreliably seat the shaft and the wax type thermoelement when thechange-over valve is manufactured. As a result, cost of the change-overvalve is increased.

In the change-over valve using the stepping motor, etc., the steppingmotor is very expensive so that cost of the four-way change-over valveis increased.

In each of the change-over valves shown in Japanese Utility ModelApplication Laying Open (KOKAI) No. 58-127276 and Japanese PatentApplication Laying Open (KOKAI) No. 59-155669 mentioned above, theelectromagnetic coil 53 is arranged outside the device body through thepipe-shaped guide 54. The plunger 55 is inserted into this guide 54 andthe valve body 52 within the device body is swung through the operatingplate 56. Therefore, the device body 52 is made compact, but theelectromagnetic coil 53 is large-sized so that the electromagnetic coil53 projects toward the exterior of the device body 52. Accordingly, thedevice body 52 and the electromagnetic coil 53 are unbalanced. Further,it is very troublesome to airtightly connect the device body 52 to theelectromagnetic coil 53 through the guide 54. Accordingly, such astructure is not practically used.

FIG. 4 shows a general air conditioner of a separating type. In FIG. 4,a heat exchanger 82 is arranged on the side of an outdoor unit 80. A1/4" service valve 84 on a liquid side is arranged on one side of thisheat exchanger 82 through a capillary tube 83. A four-way change-overvalve 87, a compressor 81 and a 3/8" service valve 85 on a gas side arearranged on the other side of the heat exchanger 82. A first piping hole1 and a third piping hole 3 of the four-way change-over valve 87 areconnected to the compressor 81. A second piping hole 2 of the four-waychange-over valve 87 is connected to the heat exchanger 82. A fourthpiping hole 4 of the four-way change-over valve 87 is connected to theservice valve 85 on the gas side. Both the service valves 84 and 85 arearranged and exposed outside the outdoor unit 80 and are connected toboth end portions of a heat exchanger 89 on the side of an indoor unit88.

A refrigerant flow is reversed by switching the four-way change-overvalve 87 so that cooling and heating operations of the air conditionerare switched.

The four-way change-over valve 87 used in the general air conditionershown in FIG. 4 is constructed as shown in FIG. 1.

As shown in FIG. 5, each of the service valve 84 on the liquid side andthe service valve 85 on the gas side has a fluid introducing port 107 ina lower portion thereof. The fluid introducing port 107 has a valve seat106 at an upper end thereof. A valve chest 108 is arranged above thevalve seat 106. A female screw 109 is formed on an inner circumferentialface of the valve chest 108. An upper opening 110 is formed above thevalve chest 108. A fluid sending-out or discharging port 111 and a port112 for a test are formed in upper side portions of the valve chest 108.A valve device body 113 s such constructional elements. A valve rod 117is screwed into the valve chest 108 of the valve device body 113. Thevalve rod 117 has a valve body 114, a male screw 115 and an O-ring 116.The valve body 114 is arranged at a lower end of the valve rod 117. Themale screw 115 is formed in a central body portion of the valve rod 117and is screwed into the female screw 109. The O-ring 116 is arranged inan upper circumferential portion of the valve rod 117 and comes in presscontact with an inner circumferential wall of the upper opening 110. Aconcave groove 118 is formed on the inner circumferential wall of theupper opening 110 above the valve rod 117. Further, an end ring 119 isarranged within this concave groove 118. An upper circumferential endedge of the upper opening 110 is caulked on an inner side thereof and avalve core 105 is mounted into the opening 112 for a test. For example,such a basic structure of the service valves is shown in JapaneseUtility Model Application Laying Open (KOKAI) No. 4-43773.

In the above general structure using the two service valves 84 and 85 onthe liquid and gas sides, the service valves each having the independentvalve structure shown in FIG. 5 are manufactured so that cost of thechange-over valve is increased. Further, a wide space for attaching theservice valves is required. In this service valve structure, therespective openings 107, 110, 111 and 112 of the valve device body 113are arranged on upper, lower and right-hand and right-hand sides of thevalve device body 113. The valve rod 117 is arranged within the valvedevice body 113. Accordingly, the service valve structure is increasedin height. Further, there are no opening and closing displays in theservice valves so that no operator can accurately attach the servicevalves to an air conditioner unless the operator is a technical expertfor attachment.

FIG. 6 is a longitudinal sectional side view of a four-way change-overvalve in accordance with a first embodiment of the present invention. InFIG. 6, a valve seat 5 is formed in a thick disk shape. This valve seat5 also constitutes a bottom wall as a portion of a valve case 10. Asshown in FIG. 7, the valve seat 5 has first to fourth piping holes 1 to4 in a planar portion thereof. The first to fourth piping holes 1 to 4are arranged at an equal pitch on a concentric circle.

A rotary valve 9 is formed in a thick disk shape. This rotary valve 9has a communicating groove 6 for connecting the first piping hole 1 tothe second piping hole 2 and also has a communicating groove 7 forconnecting the third piping hole 3 to the fourth piping hole 4. Thecommunicating grooves 6 and 7 are symmetrically arranged on a lower faceof the rotary valve 9. An operating shaft 8 is vertically arranged in acentral upper portion of the rotary valve 9. The lower face of therotary valve 9 comes in contact with an upper face of the above valveseat 5 so that the rotary valve 9 can be slidably rotated.

No two communicating holes 6 and 7 are necessarily formed in the rotaryvalve 9 having the thick disk shape. For example, a rotary valve havinga thick sector shape and at least one communicating hole may be arrangedsuch that this rotary valve can be rotated or swung.

A partition wall 12 having a shaft hole 11 in a central portion thereofis formed within a cylindrical valve case 10. A machine room 13 forarranging a drive unit is formed above this partition wall. This valvecase 10 is airtightly fixed to the upper face of the valve seat 5 suchthat the rotary valve 9 is covered with the valve case 10 in a lowerspace of the partition wall 12 and the operating shaft 8 is insertedinto the central shaft hole 11 and is projected to the machine room 13located above.

A drive unit is assembled into the machine chamber 13 of the valve case10. This drive unit rotates the operating shaft 8 of the rotary valve 9through large and small gears at many stages by rotation of a compact DCmotor 15 driven by a signal of an integrated circuit (IC) 14. In thisdrive unit, a lever 19 is perpendicularly projected to the operatingshaft 8 and comes in contact with each of two microswitches 17 and 18arranged in positions set at a rotational angle of 90°. Thus, the driveunit can rotate the operating shaft 8 by 90° in normal and reversedirections.

No motor 15 is necessarily rotated in the normal and reverse directions.For example, the motor 15 may be rotated every 90° in the samerotational direction. A driving means for rotating the rotary valve 9 isnot limited to the compact DC motor 15, but may be constructed byanother rotating means.

A communicating pipe 20 communicates the first piping hole 1 with aspace below the partition wall 12 of the valve case 10. The first pipinghole 1 is located on a high pressure side at any time when an airconditioner is operated. This high pressure is guided into the valvecase 10 so that an upper portion of the rotary valve 9 is pressedagainst the valve seat 5 by this high pressure. Accordingly, sealingproperty of the valve seat and the rotary valve is improved so thatcooling and heating abilities of the air conditioner are improved.

However, no communicating pipe 20 is necessarily required.

The four-way change-over valve 21 constructed above is operated asfollows.

As shown in FIGS. 9a and 9b, the four-way change-over valve 21 isarranged within an outdoor unit 22 of the air conditioner. The firstpiping hole 1 of the valve seat 5 is connected onto the outlet side of acompressor 23 through a pipe. The second piping hole 2 is connected to aheat exchanger 24 through a pipe. The third piping hole 3 is connectedto an inlet side of the compressor 23 through a pipe. The fourth pipinghole 4 is connected to a 3/8 service valve 25 through a pipe. Thisservice valve 25 is connected to a heat exchanger of an indoor unit.

As shown in FIGS. 7 and 9a, when the first piping hole 1 and the secondpiping hole 2 are communicated with each other through the communicatinggroove 6 of the rotary valve 9 of the four-way change-over valve 21, thethird piping hole 3 and the fourth piping hole 4 are simultaneouslycommunicated with each other through the communicating groove 7.Accordingly, a cooling operation of the air conditioner is performed.

When the rotary valve 9 is rotated 90° from the rotating state shown inFIGS. 7 and 9a, the rotary valve 9 attains a rotating state shown inFIGS. 8 and 9b. In this rotating state, the second piping hole 2 and thethird piping hole 3 are communicated with each other through thecommunicating groove 6. Simultaneously, the first piping hole 1 and thefourth piping hole 4 are communicated with each other through thecommunicating groove 7. In this case, a heating operation of the airconditioner is performed.

As mentioned above, In accordance with a first structure of the presentinvention, a four-way change-over valve for an air conditionercomprises:

first to fourth piping holes 1 to 4 sequentially arranged on aconcentric circle at a predetermined pitch in a planar portion of avalve seat 5 formed in a thick disk shape as one portion of a valve case10; and

a rotary valve 9 rotatably arranged on an upper face of this valve seat5 and having at least one communicating groove 6 for independentlyconnecting two adjacent piping holes of the four piping holes to eachother;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve 9.

In accordance with a second structure of the present invention, adriving source for rotating the rotary valve 9 is constructed by acompact DC motor 15.

In accordance with a third structure of the present invention, the firstpiping hole 1 is connected to the valve case 10 through a communicatingpipe 20.

In accordance with a fourth structure of the present invention, afour-way change-over valve for an air conditioner comprises:

first to fourth piping holes 1 to 4 sequentially arranged on aconcentric circle at an equal pitch in a planar portion of a valve seat5 formed in a thick disk shape as one portion of a valve case 10; and

a rotary valve 9 rotatably arranged on an upper face of this valve seat5 and symmetrically having communicating grooves 6, 7 for independentlyconnecting two adjacent piping holes of the four piping holes to eachother;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve 9.

In the present invention, the four-way change-over valve is constructedby the above simplified structure and the driving source is constructedby a compact DC motor. Accordingly, the piping holes connected to thevalve seat can be easily processed and the four-way change-over valvecan be easily assembled. Further, it is not necessary to arrange acomplicated mechanism for utilizing differences between refrigerantpressures. Further, similar to the general change-over valve, thecooling and heating operations can be switched even in a high pressuredifference state without projecting a bulky member such as anelectromagnetic coil from the valve case. Further, it is not necessaryto hold a current flowing state of a solenoid as In the generalchange-over valve in a heating state of the air conditioner.

Since the driving source is constructed by a compact DC motor and alldriving and control means are built-in the valve case having the samediameter as the valve seat, the entire four-way change-over valve can bemade compact and cheaply manufactured.

A service valve with a four-way change-over valve for an air conditionerin accordance with a second embodiment of the present invention willnext be described with reference to FIGS. 10 and 11. In FIG. 10, a lowerhalf section is a four-way change-over valve section and an upper halfsection is a service valve section. The construction of the four-waychange-over valve will first be described. portion in FIG. 10 and isformed in a thick disk shape. The valve seat 205 has a circular recessedportion 206 having a shallow bottom on an upper face thereof (see FIG.11). First to fourth piping holes 201 to 204 are formed on a concentriccircle at an equal pitch on a lower face of this valve seat 205. Each ofthe first to third piping holes 201 to 203 is formed in an elbow shapeconnected to an outer circumferential side of the valve seat 205. Thefourth piping hole 204 is communicated with a piping connection hole 207formed on the upper face of the valve seat 5.

The piping connection hole 207 is located between the first piping hole201 and the fourth piping hole 204 on the upper face of the valve seat205 and is slantingly communicated with the fourth piping hole 204 onthe lower face of the valve seat 205. A piping connection hole 208 islocated between the first piping hole 201 and the second piping hole 202and is formed in an elbow shape connected to the outer circumferentialside of the valve seat 205. The piping connection holes 207 and 208 arearranged on a concentric circle. A communicating hole 209 is connectedfrom an intermediate portion of the first piping hole 201 to the lowerface of the valve seat 205. A fitting hole 210 is disposed in a centralportion of the valve seat 205 on the upper face thereof. An end tipportion of a driving shaft 232 for rotating a disk shutter 227 describedlater is fitted into the fitting hole 210. A supporting hole 211 isdisposed in a central portion of the valve seat 205 on the lower facethereof. A supporting shaft of a rotary valve 212 is fitted into thesupporting hole 211.

The rotary valve 212 is formed in a thick disk shape and is located onthe lower face of the valve seat 205. Communicating grooves 213 and 214are symmetrically formed on an upper face of the rotary valve 212. Thecommunicating groove 213 connects the first piping hole 201 and thesecond piping hole 202 of the valve seat 205 to each other. Thecommunicating groove 214 connects the third piping hole 203 and thefourth piping hole 204 of the valve seat 205 to each other. A gear 215having a ring shape is formed in a central lower portion of the rotaryvalve 212. A pin 216 is formed in a central portion of the rotary valve212 on the upper face thereof. The pin 216 is fitted into the supportinghole 211 on the lower face of the valve seat 205. A rotary restrictingportion 217 is disposed in an outer circumferential portion of therotary valve 212.

A valve case 218 is formed in a cylindrical shape having a bottom. Arotary restricting projection 219 is formed on an inner circumferentialface of this valve case 218. A plurality of holes 221b are formed in abottom wall of the valve case 218. Shafts of plural gears 220 describedlater are respectively fitted into these holes 221b. The rotary valve212 is covered with the valve case 218.

A cylindrical bracket 222 has a partition plate 223 in an intermediateportion thereof. A plurality of holes 221 are formed in this partitionplate 223. The above shafts of the gears 220 are respectively fittedinto these holes 221. The bracket 222 is arranged below the valve case218 such that the bracket 222 and the valve case 218 overlap each other.

A compact motor 224 is arranged below this bracket 222. A gear shaft 225is attached to a shaft of the motor 224 and is projected upward from thepartition plate 223. The above plural gears 220 are combined with eachother between the partition plate 223 and the bottom wall of the valvecase 218. The rotary valve 212 is rotated at a low speed through thering-shaped gear 215 on a lower face of the rotary valve 212.

Reference numeral 226 designates a terminal of the compact motor 224.

The construction of the service valve section in the upper half sectionof FIG. 10 will next be described.

A disk shutter 227 is rotatably fitted into the circular recessedportion 206 on the upper face of the valve seat 205. The disk shutter227 has passing holes 228 and 229 in positions corresponding to thepiping connection holes 207 and 208 of the valve seat 205. The diskshutter 227 also has a driving hole 230 in a central portion thereof. Nodriving hole 230 is formed in a circular shape. No shape of the drivinghole 230 is especially limited. Accordingly, the driving hole 230 may beformed in the shape of a notch partially having a straight line portion231 and a circular portion as shown in FIG. 11.

A driving shaft 232 is arranged to rotate the disk shutter 227. Aslotted portion 233 is formed at a lower end of the driving shaft 232such that the slotted portion 233 is inserted into the driving hole 230.The driving shaft 232 has a ring groove 235 in an intermediate portionthereof and an O-ring 234 is fitted to this ring groove 235. A drivergroove 236 and a stepped directional mark 237 are formed at an upper endof the driving shaft 232.

A shutter cover 238 is arranged on the upper face of the valve seat 205such that the disk shutter 227 is covered with the shutter cover 238.Piping holes 239 and 240 are formed in positions of the shutter cover238 corresponding to the piping connection holes 207 and 208 of thevalve seat 205. A through hole 241 is formed in a central portion of theshutter cover 238.

The piping holes 239, 240 and the central through hole 241 are formed bypress working in a state in which a space 242 is formed on the lowerface of a peripheral portion around these holes. A washer 244 having aring shape has an O-ring 243 on a lower face thereof and is integrallyformed in the space 242 on lower faces of the piping holes 239 and 240.

A driving shaft guide 245 is fixed to the through hole 241. The drivingshaft guide 245 has an enlarged hole 246 at an internal lower endthereof. The above O-ring 234 is airtightly fitted into this enlargedhole 246. The driving shaft guide 245 is enlarged in an upper halfportion thereof through a tapered face 247. The driving shaft guide 245has a female screw 248 in an inner circumferential portion thereof.

A screw cap 249 has a hexagon head 250 which can be screwed into thefemale screw 248 of the driving shaft guide 245. A lower end portion ofthe screw cap 249 comes in press contact with the above tapered face 247so that a metallic seal is formed.

A connection pipe 251 is connected to the piping hole 239 of the shuttercover 238. The connection pipe 251 has a service port portion 252 in anintermediate portion thereof. The service port portion 252 has anunillustrated valve core. The connection pipe 251 also has a flare face253 and a male screw 254 at an end tip thereof. A connection pipe 255 issimilarly connected to the piping hole 240. This connection pipe 255also has a flare face 256 and a male screw 257 at an end tip thereof. Aflare nut is normally screwed to the end tip of each of both theconnection pipes 251 and 255.

A body case 260 is formed in a cylindrical shape having a bottom. Alower half portion 261 of this body case 260 has a diameter set suchthat the valve case 218 and the bracket 222 are fitted into this lowerhalf portion 261. An upper half portion 262 of the body case 260 has adiameter set to be slightly larger than that of the lower half portion261 such that the valve seat 205 is fitted into this upper half portion262. Pipes 263 to 266 are radially arranged in an outer circumferentialportion of the upper half portion 262. These pipes 263 to 266 arelocated in positions corresponding to the first to third piping holes201 to 203 and the piping connection hole 208 directed to an outercircumferential portion of the valve seat 205 having a thick disk shape.These pipes 263 to 266 are respectively communicated with the first tothird piping holes 201 to 203 and the piping connection hole 208. Aterminal hole 267 of the compact motor 224 is formed in a bottom portionof the body case 260. The projected terminal 226 of the motor is coveredwith a cover 268.

The above service valve with the four-way change-over valve in thesecond embodiment of the present invention is assembled in the followingorder.

First, the compact motor 224 is fixed to a lower portion of thepartition plate 223 of the bracket 222. The plural gears 220 are engagedwith each other in an upper portion of the partition plate 223. Therotary valve 212 is inserted into the valve case 218. This valve case218 is mounted onto the engaged gears 220. The gears 220 and thering-shaped gear 215 on the lower face of the rotary valve 212 arecombined with each other such that rotation of the compact motor 224 istransmitted to the ring-shaped gear 215 through the gears 220 in a speedreducing state. The terminal 226 of the compact motor 224 is theninserted into the terminal hole 267 in the body case bottom portion. Theabove combined members are fitted into the lower half portion 261 of thebody case 260.

Next, the pin 216 on the upper face of the rotary valve 212 is fittedinto the supporting hole 211 at a central lower end of the valve seat205 having a thick disk shape. The piping holes in an outercircumferential portion of the valve seat 205 are aligned and connectedto respective pipes of the body case 260. Then, the disk shutter 227 isfitted into the circular recessed portion 206 on the upper face of thevalve seat 205.

A lower end of the driving shaft 232 is fitted into the driving hole 230in a central portion of the disk shutter 227. Thereafter, the connectionpipes 251, 255 and the driving shaft guide 245 are attached to theshutter cover 238 in advance. The driving shaft 232 is inserted into acentral portion of the driving shaft guide 245 attached to the shuttercover 238 in advance. An upper face of the disk shutter 227 is coveredwith this shutter cover 238. An opening portion of the body case 260 atan upper end thereof is then caulked inside the body case 260 so thatthe shutter cover 238 is fixed.

The service valve with the four-way change-over valve in the presentinvention is arranged in an outdoor unit 280 of an air conditioner asshown in FIGS. 11 and 15.

Namely, an opening of the first piping hole 201 in a valve seat sideportion thereof is connected to the outlet side of a compressor 281through a pipe 263 of the body case 260. Similarly, an opening of thethird piping hole 203 in a valve seat side portion thereof is connectedto an inlet side of the compressor 281 through a pipe 265. An opening ofthe second piping hole 202 in a valve seat side portion thereof isconnected to a heat exchanger 282 on a side of the outdoor unit 280through a pipe 264. An opening of the piping connection hole 208 on aliquid side in a valve seat side portion thereof is connected to acapillary lube 283 through a pipe 266.

The connection pipe 251 on the gas side connected to the pipingconnection hole 207 of the service valve section is connected to a heatexchanger 289 of an indoor unit 288. The connection pipe 255 connectedto the piping connection hole 208 on the liquid side is also connectedto the heat exchanger 289 of the indoor unit 288.

The service valve with the four-way change-over valve is operated asfollows.

The driving shaft 232 of the service valve with the four-way change-overvalve is operated by a driver to rotate the disk shutter 227 so that thepassing holes 228 and 229 of the disk shutter 227 are respectivelycommunicated with the piping connection holes 207 and 208 of the valveseat 205 as shown in FIG. 11. In this communicating state, the airconditioner attains an operable state. When the first piping hole 201 isthen communicated with the second piping hole 202 through thecommunicating groove 213 of the rotary valve 212, the third piping hole203 is simultaneously communicated with the fourth piping hole 204through the communicating groove 214. Accordingly, a cooling operationof the air conditioner is performed as shown in FIG. 15.

From this cooling state, the rotary valve 212 is rotated 90° so that thesecond and third piping holes 202 and 203 are communicated with eachother through the communicating groove 213. Simultaneously, the firstand fourth piping holes 201 and 204 are communicated with each otherthrough the communicating groove 214. Thus, the cooling operation of theair conditioner is switched to a heating operation thereof.

If no passing holes 228 and 229 of the disk shutter 227 are set to bealigned with any one of the piping connection holes 207 and 208 of thevalve seat 205 at forwarding and moving times of the air conditioner, itis possible to freely detach and move the air conditioner since thepassing holes on the gas and liquid sides are closed.

When an air purging state of the air conditioner is set, the passinghole 228 of the disk shutter 227 is aligned with the piping connectionhole 208 on the liquid side. In this state, air stored within piping ofthe indoor unit is pushed out by refrigerant within the outdoor unit sothat this air is discharged into the air by pushing the valve corewithin the service port portion 252. Thus, the indoor unit is alsofilled with the refrigerant.

When a pumping-down state of the air conditioner is set, the passinghole 229 of the disk shutter 227 is aligned with the piping connectionhole 207 on the gas side, and the piping connection hole 208 on theliquid side is closed. In this state, when the air conditioner isoperated, the refrigerant on the indoor unit side is sucked and returnedto the outdoor unit side by the compressor.

A position of the disk shutter 227 and opening and closing states of theholes on the liquid and gas sides in this disk shutter position can bevisualized by a display on an upper face of the shutter cover 238 shownin FIG. 11 and the directional mark 237 of the driving shaft 232. In anoperation of the driving shaft 232, the driving shaft 232 is rotated ina state in which the hexagon head 250 of the screw cap 249 is unfastenedand detached by a spanner. When the air conditioner is forwarded, movedand operated, this screw cap 249 is screwed into the female screw 248 ofthe driving shaft guide 245. Thus, a metallic touch seal is formedbetween a lower end portion of the screw cap 249 and the tapered face247 within the driving shaft guide 245.

In rotation of the rotary valve 212, the outer circumferentialrestricting portion 217 of this rotary valve 212 comes in contact withthe restricting projection 219 in an inner circumferential portion ofthe valve case 218 so that the rotary valve 212 is stopped in apredetermined position.

FIGS. 10 and 11 show one preferred embodiment of the service valve withthe four-way change-over valve in the present invention. Accordingly,the structure of each of constructional portions of the service valvecan be suitably changed.

For example, in FIGS. 10 and 11, the body case 260 and the shutter cover238 are formed by press working, but can be also formed by casing andforging. In this case, connection pipe portions can be integrated witheach other.

The first to fourth piping holes 201 to 204 on the lower face of thevalve seat 205 are arranged on a concentric circle at an equal pitch.This pitch is determined by the relation in shape between thecommunicating grooves 213 and 214 of the rotary valve 212 and a rotatingamount of the rotary valve 212. Accordingly, the first to fourth pipingholes 201 to 204 can be arranged at pitches except for the equal pitch.

Only one of the communicating grooves 213 and 214 may be formed andarranged. In this case, for example, it is sufficient to form the rotaryvalve 212 in a sector shape such that two piping holes are communicatedwith each other through this one communicating groove and the pipingholes except for these two piping holes are set to be opened.

The distances between the piping connection holes 207 and 208 on theupper face of the valve seat 205 and the passing holes 228 and 229 ofthe disk shutter 227 are set such that operable, all hole closing, airpurging and pumping-down operations of the air conditioner are performedin four rotational positions of the disk shutter 227 every 90°. However,required operations of the air conditioner may be performed in threerotational positions of the disk shutter 227 every 120° in the case ofthe air conditioner of a type in which no air purging operation isperformed.

When a strainer is attached to the air conditioner, the strainer may beattached into the piping connection holes 207, 208, the connection pipes251, 255, or the pipes 265, 266 of the body case 260.

No metallic touch seal means of the screw cap 249 is necessarilyrequired. Further, no driving means of the disk shutter 227 is alsoespecially required.

No reduction gear means for reducing a rotational speed of the compactmotor 224 is limited to plural gears.

A service valve with a four-way change-over valve for an air conditionerin accordance with a third embodiment of the present invention will nextbe described with reference to FIGS. 12 to 14. This service valve in thethird embodiment is different from that in the second embodiment shownin FIGS. 10 and 11 with respect to the constructions of a valve seat anda rotary valve. The other constructional portions are similar to thosein the second embodiment. Accordingly, the same constructional portionsas the second embodiment are designated by the same reference numeralsand an explanation thereof is omitted in the following description.

A valve seat 205a is located in a central portion of the service valveshown in FIG. 12. The valve seat 205a has a thick disk shape in which acircular recessed portion 206 having a shallow bottom is formed on anupper face of the valve seat 205a. A valve chest 205b is formed in acentral portion of the valve seat 205a. First to fourth piping holes 201to 204 are formed in an outer circumferential portion of the valve seat205a and are sequentially arranged at an equal pitch in four directions.Each of the first to third piping holes 201 to 203 is formed in theshape of a straight line connected to an outer circumferential side faceof the valve seat 205a. The fourth piping hole 204 is communicated witha piping connection hole 207 formed on the upper face of the valve seat205a and described later.

The valve seat 205a has sector chambers stepped on a plane andsymmetrically arranged. Rotation of a rotary valve 212a formed in abutterfly shape and described later is restricted by a stepped portionof the valve seat 205a.

Piping connection holes 207 and 208 are formed on a concentric circle onthe upper face of the valve seat 205a. The piping connection hole 207 isarranged on a side of the fourth piping hole 204 over the first pipinghole 201 and is communicated with the fourth piping hole 204 (see FIG.13). The piping connection hole 208 is formed in an elbow shape on aside of the second piping hole 202 and is connected to an outercircumferential side face of the valve seat 205a.

The rotary valve 212a in a butterfly shape is located in a centralportion of the valve seat 205a. An outer circumferential surface of therotary valve 212a is coated with rubber. The rotary valve 212a has a pin216 in an upper portion thereof. The rotary valve 212a also has a gearshaft 216a in a lower portion thereof.

A valve seat cover 218a is formed in a disk shape and is located on alower face of the valve seat 205a. A rotary restricting projection 219ais formed on an upper face of the valve seat cover 218a and is locatedin a position corresponding to a step of the sector chambers of thevalve seat 205a. A hole 221a is formed in a central portion of the valveseat cover 218a. The gear shaft 216a formed in the lower portion of therotary valve 212a is fitted into this hole 221a. The valve chest 205b isformed by this valve seat cover 218a and the valve seat 205a.

In this third embodiment, the rotary valve 212a is formed in a butterflyshape. However, for example, the rotary valve may be formed in acolumnar shape.

Namely, when the valve chest 205b in the central portion of the valveseat 205a is formed in a cylindrical shape, the rotary valve may berotatably formed in a columnar shape within this valve chest 205b suchthat each of communicating grooves independently connects two adjacentpiping holes of the first to fourth piping holes to each other and issymmetrically arranged in the rotary valve.

The above-mentioned service valve is assembled in the following order.

As shown in FIGS. 13 and 14, the rotary valve 212a is mounted into thevalve chest 205b in the central portion of the valve seat 205a. Thevalve seat 205a and the rotary valve 212a are covered with the valveseat cover 218a from below. The rotary valve 212a iis rotatably held ina state in which the gear shaft 216a in a lower portion of the rotaryvalve 212a is projected downward from the hole 221a of the valve seatcover 218a.

Next, the gear shaft 216a is engaged with a lowest speed gear of pluralgears 220 within a bracket 222 explained in the second embodiment. Inthis engaging state, as shown in FIG. 14, the bracket 222 and the valveseat 205a are mounted into a body case 260.

An assembly order of the other constructional portions is similar tothat in the second embodiment. Accordingly, an explanation of thisassembly order is omitted in the following description. Further, anoperation of this service valve is also similar to that in the secondembodiment except for the difference in structure of the rotary valve.Accordingly, an explanation of this operation is also omitted in thefollowing description.

As mentioned above, in accordance with a fifth structure of the presentinvention, a service valve with a four-way change-over valve for an airconditioner is characterized in that both service valves on liquid andgas sides of a refrigerant circuit are integrated with each other andare further integrated with the four-way change-over valve as one valveunit with one valve seat as a common valve seat.

In accordance with a sixth structure of the present invention, a servicevalve with a four-way change-over valve for an air conditionercomprises:

first to fourth piping holes 201 to 204 formed on a lower face of avalve seat 205 having a thick disk shape and sequentially arranged on aconcentric circle at a predetermined pitch;

three piping holes among the four piping holes 201 to 204 beingcommunicated with a side portion of the valve seat; and

a rotary valve 212 rotatably arranged on the lower face of the valveseat 205 and having one or two communicating grooves 213, 214independently connecting two adjacent piping holes of the four pipingholes 201 to 204 to each other and symmetrically arranged;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve 212;

the service valve further comprising:

two piping connection holes 207, 208 formed on an upper face of thevalve seat 205 such that the two piping connection holes 207, 208 areshifted from each other on a concentric circle;

one of the two piping connection holes 207, 208 being connected to apiping hole except for the three piping holes communicated with the sideportion on the lower face of the valve seat;

the other piping connection hole being communicated with the sideportion of the valve seat;

a disk shutter 227 rotatably arranged on the upper face of the valveseat 205 and having two passing holes 228, 229 in positionscorresponding to the piping connection holes 207, 208; and

a shutter cover 238 arranged above the disk shutter 227 and havingpiping holes 239, 240 in positions corresponding to the two passingholes 228, 229 of the disk shutter 227;

cooling and heating operable states of the air conditioner and anoperating state of the air conditioner except for the cooling andheating operable states being switched by rotating the disk shutter 227.

In accordance with a seventh structure of the present invention, astrainer is attached into each of the piping connection holes 207, 208.

In accordance with an eighth structure of the present invention, drivingmeans for rotating the rotary valve 212 is constructed by a compactmotor 224.

In accordance with a ninth structure of the present invention, a servicevalve with a four-way change-over valve for an air conditionercomprises:

a valve chest 205b formed in a central portion of a valve seat 205ahaving a thick disk shape;

first to fourth piping holes 201 to 204 each formed in an outercircumferential portion of the valve chest 205b and sequentiallyarranged at a predetermined pitch in four directions;

three piping holes of the four piping holes 201 to 204 beingcommunicated with a side portion of the valve seat 205a; and

a rotary valve 212a rotatably arranged within the valve chest 205b inthe central portion of the valve seat and independently connecting twoadjacent piping holes among the four piping holes 201 to 204 to eachother;

cooling and heating operations of the air conditioner being switched byrotating the rotary valve 212a;

the service valve further comprising:

two piping connection holes 207, 208 formed on an upper face of thevalve seat 205a such that the two piping connection holes 207, 208 areshifted from each other on a concentric circle;

one of the two piping connection holes 207, 208 being connected to apiping hole except for the three piping holes communicated with the sideportion of the valve seat;

the other piping connection hole being communicated with the sideportion of the valve seat;

a disk shutter 227 rotatably arranged on the upper face of the valveseat 205a and having passing holes 228, 229 in positions correspondingto the piping connection holes 207, 208; and

a shutter cover 238 arranged above the disk shutter 227 and havingpiping holes 239, 240 in positions corresponding to the two pipingconnection holes 207, 208;

cooling and healing operable states of the air conditioner and anoperating state of the air conditioner except for the cooling andheating operable states being switched by rotating the disk shutter 227.

In accordance with a tenth structure of the present invention, astrainer is attached into each of the piping connection holes 207, 208.

In accordance with an eleventh structure of the present invention,driving means for rotating the rotary valve 212a is constructed by acompact motor 224.

In accordance with a twelfth structure of the present invention, therotary valve 212a is formed in a butterfly shape.

In accordance with a thirteenth structure of the present invention, therotary valve 212a is formed in a columnar shape such that twoindependent communicating holes are symmetrically formed in a bodyportion of the rotary valve 212a.

As mentioned above, the service valve with a four-way change-over valvein the second and third embodiments of the present invention has twopiping connection holes for the service valve formed on an upper face ofone valve seat having a thick disk shape. Four piping holes for thefour-way change-over valve are formed on a lower face of the valve seator in a valve chest in a central portion of the valve seat. A diskshutter is rotatably arranged on the upper face of the valve seat. Theservice valve is opened and closed by rotating this disk shutter. Arotary valve is arranged on the lower face of the valve seat or withinthe central valve chest. Cooling and heating operations of an airconditioner are switched by rotating this rotary valve. General threefunctions of two service valves and a four-way change-over valve areunited as one function so that a compact service valve is provided.

Accordingly, the service valve can be attached to one portion of the airconditioner on an outdoor unit side. Therefore, it is not necessary tosolder a pipe for connecting the service valve to the four-waychange-over valve. Thus, the number of complicated operations in amanufacturing process of the air conditioner is reduced and a space forthe service valve is totally reduced so that cost of the service valveis reduced.

It is generally necessary to open and close the service valve in twopositions on liquid and gas sides. However, in the present invention,all opening and closing operations of the service valve can be performedby only unfastening and detaching a screw cap and rotating one drivingshaft. Accordingly, the service valve can be easily treated and simplyoperated. Opening and closing states of the service valve displayed onthe upper face of a shutter cover can be easily confirmed in accordancewith the direction of a directional mark in an upper portion of thedriving shaft. Accordingly, there is no error in operation of theservice valve.

Further, the four-way change-over valve has the above-mentionedsimplified structure and is operated by a compact motor. Accordingly, itis easy to process piping holes of the valve seat and assembly thefour-way change-over valve. Further, no complicated mechanism forutilizing a difference in pressure is required to switch the cooling andheating operations. Accordingly, similar to the general service valve,the cooling and heating operations can be switched even in a highpressure difference state. Further, different from the general servicevalve, it is not necessary to hold an electric current flowing state ofthe service valve even in a heating state of the air conditioner.

FIG. 16 shows a valve for an air conditioner in accordance with a fourthembodiment of the present invention.

In FIG. 16, a flat valve case 301 has a circular recessed portion 302with a shallow bottom on an upper face thereof. The flat valve case 301also has two piping connection holes 303 and 304 shifted from each otherat a phase angle of 90° on a concentric circle. Each of ring grooves 305and 305 is formed on an upper face of each of the piping connectionholes 303 and 304 in an outer circumference thereof. An O-ring 306 isfitted into each of the ring grooves 305.

A fitting hole 307 is formed in a central portion of the circularrecessed portion 302. An end tip portion of a driving shaft 315described later is fitted into this fitting hole 307. Reference numerals308 and 309 respectively designate an attachment hole and a sealpacking.

A disk shutter 310 is rotatably fitted into the circular recessedportion 302. The disk shutter 310 has passing holes 311 and 312 inpositions corresponding to the piping connection holes 303 and 304 ofthe valve case 301. The passing holes 311 and 312 respectively have thesame diameters as the piping connection holes 303 and 304. The diskshutter 310 has a non-circular driving hole 313 in a central portionthereof. No non-circular shape of the driving hole 313 is especiallylimited. For example, the driving hole 313 may be formed in the shape ofa circular notch partially having a straight line portion 314 as shownin FIG. 16.

The driving shaft 315 is disposed to rotate the disk shutter 310. Thedriving shaft 315 has a slotted portion 316 at a lower end thereofformed such that the slotted portion 316 is inserted into the drivinghole 313. The driving shaft 315 has a ring groove 317 in an intermediateportion thereof. An O-ring is fitted to this ring groove 317. An upperhalf portion of the driving shaft 315 is formed in an elliptical shapehaving a small diameter. Slotted portions are formed on both sides ofthis upper half portion of the driving shaft 315 at an upper endthereof.

A valve cover 320 can be airtightly aligned and attached to the flatvalve case 301 through the seal packing 309. The valve cover 320 haspiping holes 318 and 319 on an upper face thereof. The piping holes 318and 319 are respectively formed in positions corresponding to the pipingconnection holes 303 and 304 of the valve case 310. Each of the pipingholes 318 and 319 is extended in an L-shape until an outercircumferential side face of the valve cover 320. The valve cover 320has a shaft hole 321 in a central portion thereof. The driving shaft 315can be rotatably fitted into the shaft hole 321. Reference numeral 341designates an attachment hole.

As shown in FIG. 18, the shaft hole 321 of the valve cover 320 has adiameter set such that a central portion of the driving shaft 315 isfitted into a lower face side of the shaft hole 321. A small diameterportion 322 is formed above the shaft hole 321. A stepped hole is formedabove this small diameter portion 322 and is composed of a smalldiameter hole 323 and a large diameter hole 324. A female screw 325 isformed on an inner circumferential face of the large diameter hole 324.A chamfered valve seat 326 is formed at an upper end edge of the smalldiameter hole 323 of the stepped hole.

A ring groove 305 is also formed around a valve cover inner face side ofthe piping hole 319. An O-ring 306 is also fitted into this ring groove305.

An operating shaft 330 has a fitting recessed portion 327 at a lower endthereof. The elliptical head portion of the driving shaft 315 is fittedinto this fitting recessed portion 327. The operating shaft 330 has aflange 328 in a lower outer circumferential portion thereof. A lowerface of this flange 328 is formed as a slanting face 329 and correspondsto a valve seat portion of the above stepped hole.

A lock bolt 333 has a hole 331 in a central portion thereof. Theoperating shaft 330 is inserted into this hole 331. The lock bolt 333has a male screw 332 screwed into the female screw 325 in a lower outercircumferential portion thereof. A hexagon head 334 is formed in anupper outer circumferential portion of the lock bolt 333. A handle 335has an arrow 336 on an upper face thereof. The handle 335 is fitted intoan upper end portion of the operating shaft 330 and is fixed by a lockpin 337.

As shown in FIG. 19, a valve cover 338 has a display portion 339 showingopening and closing states of the valve in rotational positions of thedisk shutter 310 in four directions on an upper face of the valve cover338 in an outer circumferential portion thereof.

The O-rings 306, the disk shutter 310, the driving shaft 315 fitting theO-ring thereonto, etc. are assembled into the valve case 301 byattachment bolts 340. Thereafter, the valve case 301 is covered with thevalve cover 320 through the seal packing 309. Thus, as shown in FIGS. 17and 18, the disk shutter 310, the driving shaft 315, etc. are fixed andintegrated with the valve case 301 by inserting and fixing each of theattachment bolts 340 into an attachment hole 341 of the valve cover 320and the attachment hole 308 of the valve case. The integrated valve caseis attached to an outdoor unit of the air conditioner.

A connection pipe 342 is connected to the piping hole 318 of the valvecover 320. The connection pipe 342 has a service port portion 343 havinga valve core in an intermediate portion thereof. The connection pipe 342has a flare face 344 at an end tip thereof. A connection pipe 345 issimilarly connected to the piping hole 319. The connection pipe 345 alsohas a flare face 344 at an end tip thereof. As shown in FIG. 19, a flarenut 346 is normally screwed onto the end tip of each of the connectionpipes 342 and 345.

The valve case 301 and the valve cover 320 mentioned above are formed bycasting in the present invention, but can be also formed by pressworking. In this case, an L-shaped pipe is welded to locate an openingportion of each of the piping holes 318 and 319 in a side portion of thevalve cover 320.

In the above fourth embodiment, the circular recessed portion 302 isformed on an upper face of the valve case 301. This circular recessedportion 302 may be arranged on a side of the valve cover 320. In thiscase, the upper face of the valve case 301 is formed in a flat shape.

Further, the driving hole 313 is formed in a central portion of the diskshutter 310. However, the driving shaft 315 may be integrally formed inthe central portion of the disk shutter 310.

An operation of the above valve for an air conditioner will next bedescribed.

The 3/8" piping connection hole 303 on a valve case side of the abovevalve structure is connected to the side of a four-way change-over valveof an outdoor unit. This four-way change-over valve side is called a gasside in the following description. The other 1/4" piping connection hole304 is connected to the side of a capillary tube of the outdoor unit.This capillary tube side is called a liquid side in the followingdescription. A valve function in these connecting states will next beexplained with reference to FIG. 21a to 21d. FIGS. 21a to 21d show onlythe relation between the piping connection holes 303, 304 of the valvecase 301 and the passing holes 311, 312 of the disk shutter 310. In thevalve cover 320, the piping holes 318 and 319 are respectively arrangedin positions corresponding to both the piping connection holes 303 and304. Accordingly, when one or both of the piping connection holes 303and 304 of the valve case 301 are respectively aligned with one or bothof the passing holes 311 and 312 of the disk shutter 310, one or both ofthe piping connection holes 303 and 304 are respectively communicatedwith one or both of the piping holes 318 and 319 on the valve coverside.

FIG. 21a shows a state in which the valve for an air conditioner isforwarded and moved. In this state, no passing holes 311 and 312 of thedisk shutter 310 are aligned with any one of the piping connection holes303 and 304 of the valve case 301 so that the piping connection holesare closed on the gas and liquid sides. In this state, the piping holes318 and 319 of the valve cover 320 are communicated with an evaporatoron an indoor unit side.

FIG. 21b shows an air purging state of the valve. In this state, thedriving shaft 315 is rotated so that the passing hole 311 of the diskshutter 310 is aligned with the piping connection hole 304 on the liquidside. In this state, air stored within piping on an indoor unit side ispushed out by refrigerant within an outdoor unit so that this air isdischarged into the air by pushing the valve core within the serviceport portion 343. Thus, the indoor unit is also filled with therefrigerant.

FIG. 21c shows a state in which the air conditioner is operated. In thisstate, the passing holes 311 and 312 of the disk shutter 310 arerespectively aligned with the piping connection holes 303 and 304. Inthis state, the refrigerant is circulated between the outdoor and indoorunits so that a cooling or heating operation of the air conditioner canbe performed.

FIG. 21d shows a pumping-down state of the valve for the airconditioner. In this state, the passing hole 312 of the disk shutter 310is aligned with the piping connection hole 303 on the gas side, and thepiping connection hole 304 on the liquid side is closed. In this state,when the air conditioner is operated, the refrigerant on the indoor unitside is sucked by a compressor and is returned onto the outdoor unitside. Thereafter, if the state shown in FIG. 21a is set by rotating thedisk shutter 310, each of the piping connection holes is completelyclosed so that the air conditioner can be freely detached and moved.

A position of the disk shutter 310 and opening and closing states of theabove holes on the liquid and gas sides in this disk shutter positioncan be visualized by a display on the upper face of the valve cover 338and the arrow 336 of the handle 335 shown in FIG. 19. In FIG. 19, "G"shows the above gas side and "L" shows the above liquid side. When thehandle 335 is operated, the handle 335 is rotated in a state in whichthe hexagon head 334 of the lock bolt 333 shown in FIG. 18 is unfastenedby a spanner. This lock bolt 333 is fastened when the air conditioner isforwarded, moved and operated. Thus, the slanting face 329 on a lowerflange face of the operating shaft 330 comes in press contact with avalve seat portion of the stepped hole in a central portion of the valvecover 320 so that a metallic touch seal is formed.

For example, it is possible to provide a seal function by forming acopper packing, etc. instead of this metallic touch seal on the lowerface of the flange 328 and an upper face of the small diameter hole 323of the stepped hole.

In the above fourth embodiment, the stepped hole is formed in an uppercentral portion of the valve cover 320 to rotate the driving shaft 315.The disk shutter 310 is rotated by using the operating shaft 330 havinga flange, the lock bolt 333, the handle 335, etc. in this stepped hole.However, the operating shaft, etc. are not necessarily required if theO-ring 306 arranged around the driving shaft 315 sufficiently seals theshaft hole 321 in the central portion of the valve cover so that norefrigerant is leaked. In this case, for example, if the driving shaft315 can be rotated, a simple T-shaped handle and an L-shaped handle as ahexagon shaft may be used.

The valve cover 338 having the display portion 339 showing opening andclosing states of the valve is arranged on an upper face of the valve inan outer circumferential portion thereof. However, this valve cover 338is not necessarily required. For example, the display portion 339 may bedirectly formed on an upper face of the valve cover 320. In this case,the valve cover 338 is omitted.

In the above fourth embodiment, the piping connection holes 303 and 304are shifted from each other at a phase angle of 90° to provide fourstates composed of operating, forwarding-moving, pumping-down and airpurging states of the air conditioner. When no air purging state isrequired, the piping connection holes 303 and 304 may be shifted fromeach other at an angle of 120°.

As mentioned above, in accordance with a fourteenth structure of thepresent invention, a valve for an air conditioner comprises;

a flat valve case 301 having a circular recessed portion 302 with ashallow bottom on an upper face thereof and having two piping connectionholes 303, 304 shifted from each other at a phase angle of 90° or 120°on a concentric circle;

a disk shutter 310 rotatably arranged within the circular recessedportion 302 of the flat valve case 301 and having passing holes 311, 312in positions corresponding to the piping connection holes 303,.304;

the disk shutter 310 further having a driving shaft 315 in a centralportion thereof; and

a valve cover 320 having piping holes 318, 319 in positionscorresponding to the two piping connection holes 303, 304;

the valve cover 320 further having a shaft hole 321 in a central portionthereof formed such that the driving shaft 315 can be rotatably fittedinto this shaft hole 321; and

the valve cover 320 being fixed to the valve case 301 such that thevalve cover 320 airtightly covers the disk shutter 310 and the drivingshaft 315 from above.

In accordance with a fifteenth structure of the present invention, thevalve case 301 and the valve cover 320 are molded by press working.

In accordance with a sixteenth structure of the present invention, eachof the piping holes 318, 319 of the valve cover 320 is communicated witha side face of the valve cover.

In accordance with a seventeenth structure of the present invention, thevalve further comprises:

a stepped hole formed in an upper half portion of the shaft hole 321 inthe central portion of the valve cover;

the stepped hole having a large diameter hole 324 in an upper portionthereof;

the stepped hole having a small diameter hole 323 in a lower portionthereof;

a female screw 325 formed on an inner circumferential face of the upperlarge diameter hole 324;

an operating shaft 330 having a fitting recessed portion 327 at a lowerend thereof fitted onto a head portion of the driving shaft 315;

the operating shaft 330 further having a flange 328 in a lower outercircumferential portion thereof;

a lock bolt 333 having a hole 331 in a central portion thereof forreceiving the operating shaft 330;

the lock bolt 333 having a male screw 332 in a lower outer circumferencethereof;

the lock bolt 333 having a hexagon head 334 in an upper outercircumference thereof; and

a handle 335 arranged in a head portion of the operating shaft 330; and

the valve is constructed by fitting the head portion of the drivingshaft 315 into the fitting recessed portion 327 of the operating shaft330, and screwing the lock bolt 333 into the female screw 325 above thestepped hole through the operating shaft 330.

In accordance with an eighteenth structure of the present invention, aseal function is provided between a lower face of the flange 328 of theoperating shaft 330 and an upper end edge of the small diameter hole 323in the stepped hole.

In accordance with a nineteenth structure of the present invention, anarrow 336 is formed in an upper portion of the handle 335;

an upper portion of the valve cover 320 is covered with a second valvecover 338; and

a display 339 showing opening and closing states of the valve in arotational position of the disk shutter 310 is formed on an upper faceof this second valve cover 338 in an outer circumferential portionthereof.

As mentioned above, in the valve for an air conditioner in the fourthembodiment, the disk shutter is rotatably arranged within one flat valvecase. The valve is opened and closed by rotating this disk shutter.Accordingly, the valve is reduced in height so that the valve is madecompact. Further, the valve has a good appearance in a state in whichthe valve is attached onto the side of an outdoor unit. All opening andclosing operations of the valve can be performed by only unfastening thelock bolt and rotating the handle so that the valve is easily treatedand simply operated. Further, opening and closing states of the valvedisplayed on an outer circumferential face of the valve cover can beeasily confirmed by the direction of a displayed arrow in an upperportion of the handle so that there is no error in operation of thevalve.

Many widely different embodiments of the present invention may beconstructed without departing from the spirit and scope of the presentinvention. It should be understood that the present invention is notlimited to the specific embodiments described in the specification,except as defined in the appended claims.

What is claimed is:
 1. A service valve with a four-way change-over valvefor an air conditioner, comprising:a valve seat formed in a thick diskshape; a valve chest disposed in a center of said valve seat; threefirst piping holes penetrating said valve seat, each of said firstpiping holes having a first opening communicating with said valve chestand having a second opening located on a circumferential side surface ofsaid valve seat; a second piping hole penetrating said valve seat, saidsecond piping hole having a first opening communicating with said valvechest and having a second opening located on one plane surface of saidvalve seat, said first openings of said first and second piping holesbeing sequentially arranged at predetermined angular distances in saidvalve chest; a third piping hole penetrating said valve seat, said thirdpiping hole having a first opening located on said circumferential sidesurface of said valve seat and having a second opening located on saidone plane surface of said valve seat, said the second openings of saidsecond and third piping holes being sequentially arranged on aconcentric circle on said one plane surface; a rotary valve contained insaid valve chest for selectively communicating with each other twoadjacent openings of said first openings of said first and second pipingholes; a shutter cover disposed above said one plane surface of saidvalve seat and having two fourth piping holes respectively correspondingto said second openings of said second and third piping holes; and adisk shutter rotatably disposed between said shutter cover and said onesurface of said valve seat and having two through holes respectivelycorresponding to said second openings of said second and third pipingholes so as to switch a cooling/heating operable state of said airconditioner and the other state of said air conditioner.
 2. A servicevalve with a four-way change-over for an air conditioner as claimed inclaim 1, wherein the rotary valve is formed in a butterfly shape.
 3. Aservice valve with a four-way change-over valve for an air conditioneras claimed in claim 1, wherein the rotary valve is formed in a columnarshape that two independent communicating holes are symmetrically formedin a body portion of the rotary valve.